(From the Pacific Printer.)

To Copy Printed or Written Matter.—Printed matter may be copied on any paper of an absorbent nature, by damping the surface with a weak solution of acetate of iron, and pressing in an ordinary copying press. Old writing may also be copied on unsized paper if wet with a weak solution of sulphate of iron mixed with a small solution of sugar syrup.

Harmony of Tints.—Gray sets off a color better than either black or white. White, gold, or black will serve as an edging to any color. A white ground has a tendency to make colors upon it appear darker, while a black ground has a contrary effect. In the association of two tones of one color, the effect will be to lighten the light shade and darken the other. The fact that incongruous colors are often harmoniously combined in nature is no guarantee that they may be similarly applied in art.

Spirits of Wine for cleaning off Copyable Ink.—To clean rollers used for printing copying inks, it is best to avoid water, which, it is claimed, weakens them, Spirits of wine proves much more efficient: it takes the ink off immediately, does not injure the rollers, and as it vaporizes almost instantaneously they may be used directly.

To Thin Copying Ink.—When copying-ink becomes hard or thick, as it will do on exposure to the air, it can readily be reduced to proper consistency by the addition of a few drops of glycerine. Add slowly, and test till right.

Basis for Ground Tints.—To make a good ground tint, use three pounds of magnesia ground up in a half a gallon of plate oil. This forms a transparent mass from which, by the addition of colors, as black, vermilion, lemon-yellow and bronze blue, innumerable tints may be manufactured, such as green, brown, lead, gray, buff, salmon, flesh-pink, purple, &c.